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Title: Maximum energy product at elevated temperatures for hexagonal strontium ferrite (SrFe12O19) magnet

Abstract

The electronic structure of hexagonal strontium ferrite (SrFe12O19) was calculated based on the density functional theory (DFT) and generalized gradient approximation (GGA). The GGA+U method was used to improve the description of localized Fe 3d electrons. Three different effective U (U-eff) values of 3.7, 7.0, and 10.3 eV were used to calculate three sets of exchange integrals for 21 excited states. We then calculated the temperature dependence of magnetic moments m(T) for the five sublattices (2a, 2b, 12k, 4f(1), and 4f(2)) using the exchange integrals. The m(T) of the five sublattices are inter related to the nearest neighbors, where the spins are mostly anti-ferromagnetically coupled. The five sublattice m(T) were used to ()brain the saturation magnetization M-s(T) of SrFe12O19, which is in good agreement with the experimental values. The temperature dependence of maximum energy product. ((BII)(max)(T)) was calculated using the calculated M-s(T). (C) 2013 Elsevier B.V. All rights reserved.

Authors:
; ; ; ; ; ; ; ; ;
Publication Date:
Sponsoring Org.:
USDOE Advanced Research Projects Agency - Energy (ARPA-E)
OSTI Identifier:
1211066
DOE Contract Number:  
DE-AR0000189
Resource Type:
Journal Article
Journal Name:
Journal of Magnetism and Magnetic Materials
Additional Journal Information:
Journal Volume: 355; Journal ID: ISSN 0304-8853
Country of Publication:
United States
Language:
English

Citation Formats

Park, J, Hong, YK, Kim, SG, Kim, S, Liyanage, LSI, Lee, J, Lee, W, Abo, GS, Hur, KH, and An, SY. Maximum energy product at elevated temperatures for hexagonal strontium ferrite (SrFe12O19) magnet. United States: N. p., 2014. Web. doi:10.1016/j.jmmm.2013.11.032.
Park, J, Hong, YK, Kim, SG, Kim, S, Liyanage, LSI, Lee, J, Lee, W, Abo, GS, Hur, KH, & An, SY. Maximum energy product at elevated temperatures for hexagonal strontium ferrite (SrFe12O19) magnet. United States. https://doi.org/10.1016/j.jmmm.2013.11.032
Park, J, Hong, YK, Kim, SG, Kim, S, Liyanage, LSI, Lee, J, Lee, W, Abo, GS, Hur, KH, and An, SY. 2014. "Maximum energy product at elevated temperatures for hexagonal strontium ferrite (SrFe12O19) magnet". United States. https://doi.org/10.1016/j.jmmm.2013.11.032.
@article{osti_1211066,
title = {Maximum energy product at elevated temperatures for hexagonal strontium ferrite (SrFe12O19) magnet},
author = {Park, J and Hong, YK and Kim, SG and Kim, S and Liyanage, LSI and Lee, J and Lee, W and Abo, GS and Hur, KH and An, SY},
abstractNote = {The electronic structure of hexagonal strontium ferrite (SrFe12O19) was calculated based on the density functional theory (DFT) and generalized gradient approximation (GGA). The GGA+U method was used to improve the description of localized Fe 3d electrons. Three different effective U (U-eff) values of 3.7, 7.0, and 10.3 eV were used to calculate three sets of exchange integrals for 21 excited states. We then calculated the temperature dependence of magnetic moments m(T) for the five sublattices (2a, 2b, 12k, 4f(1), and 4f(2)) using the exchange integrals. The m(T) of the five sublattices are inter related to the nearest neighbors, where the spins are mostly anti-ferromagnetically coupled. The five sublattice m(T) were used to ()brain the saturation magnetization M-s(T) of SrFe12O19, which is in good agreement with the experimental values. The temperature dependence of maximum energy product. ((BII)(max)(T)) was calculated using the calculated M-s(T). (C) 2013 Elsevier B.V. All rights reserved.},
doi = {10.1016/j.jmmm.2013.11.032},
url = {https://www.osti.gov/biblio/1211066}, journal = {Journal of Magnetism and Magnetic Materials},
issn = {0304-8853},
number = ,
volume = 355,
place = {United States},
year = {Tue Apr 01 00:00:00 EDT 2014},
month = {Tue Apr 01 00:00:00 EDT 2014}
}